Project Summary Stress is a common part of daily life, and our ability to regulate our emotions in stressful situations heavily determines our well-being and health. Importantly, emotion regulatory abilities generally improve with age, and relative to earlier parts of the life span, later life is characterized by shifts toward positivity: everyday emotional experience is on the whole filled with less negativity, and the processing of emotional information shifts toward the positive. Given older adults? general improvement in well- being and emotional health, it may be assumed that older adults are better than younger adults at responding to and regulating stress. Although age-related emotional strengths in later life can improve our responses to some types of stressors (e.g., interpersonal conflict), age-related vulnerabilities may compromise the ability to regulate emotions in other contexts. For instance, declines in deliberative cognitive processing, increased sensitivity to threatening evaluations of cognitive performance, and stress-induced physiological dysregulation may all impact the ability of older adults to regulate stress. This project aims to understand situations under which older adults might non-optimally react to and ineffectively regulate stress, and how to utilize their strengths to mitigate emotional dysregulation under stress. Specifically, this research will: (1) explore adult age differences in emotional and physiological reactivity to and regulation of interpersonal versus cognitively evaluative stressors, (2) demonstrate whether older adults capitalize more on positivity when regulating stress responses than do younger adults, and (3) examine the potential protective effect of emotion regulation in buffering the influence of genetic risk on cognitive functioning. These aims will be met through two laboratory experiments that examine the effects of interpersonal conflict versus cognitively evaluative stressors on emotion regulation and physiological reactivity and recovery (e.g., cardiac output, heart rate, blood pressure) in older and younger adults. In addition, the proposed research will examine how positive contexts (i.e., exposure to positive stimuli) may influence emotional and physiological responsivity and regulation during stressful situations. Given the importance of positive emotions in the context of stress, leveraging age-related positivity to enhance regulatory behaviors has significant implications for healthy aging. Finally, the project will explore whether emotion regulation moderates the effects of deleterious genetic risk factors on cognitive functioning. By pursuing these aims, this project promises to: better inform our understanding of how the strengths and vulnerabilities of advanced age impact our ability to regulate our emotions in different stressful situations, provide insight into how drawing on the strengths of later life may assuage the detrimental effects of stress, and highlight the utility of emotion regulation in protecting against age-related cognitive decline.